Not easy to give a good answer, I think the only ones who have any chance of knowing are the ones that have kept magazines with all proper results since the late 80's.
Also, afaik, the official "circuit records" were not the fastest single laps, but the fastest times through the qualification rounds. So the best time over 4 laps were used as the records. I know that Martin Schanche was the first one to beat any Gr.B record in 1994, when he did a 2.32 (over 4 laps) at Valkenswaard.
I know that Ludvig Hunsbedt was 4 seconds off the record at Lyngås in 1996 which Schanche set in 91 or 92, and I am not sure anyone ever got as close as what Ludvig did that day. If I still had a working VHS player, (and my parents haven't thrown the VHS's away) I might still have the whole 2nd day of the NRK-coverage from Lyngås, where Ludvig set the time, and the year of the record was mentioned. But I know some was recorded over it as well, so I might have lost it.
I would not be surprised to see track records from the Gr.B still standing, or rather, that Gr.B records were still standing when the Joker lap was introduced.
On a sidenote, I know that TV-Media still have all footage (and thus might have times) from all rounds from the mid 80's to at least mid 90's, maybe even it starts earlier and ends later. But they don't see it economically viable to get the footage out on a digital platform sadly.
EDIT: NRK and TV-Media are Norwegian companies, I expect MatsNorway to know the names, but I forgot that it is not a Norwegian forum 
Edited by Myrvold, 07 February 2018 - 21:01.